# =============================================================================
# Projet : AIR — Accounting Intermediate Representation
# Auteur : Simon-Pierre Boucher
# Contact : contact@spboucher.ai
# Fichier : journal.py
# Description : Compiled output types — accounts, journal lines/entries, compiled journal.
# =============================================================================
"""Journal types: what the AIC compiler PRODUCES (never what the LLM writes).

Every journal line carries a provenance node id, so any posted figure can be
traced back through tax/FX derivations to the source economic event and its
document.
"""
from __future__ import annotations

import enum
from dataclasses import dataclass, field
from datetime import date
from decimal import Decimal

from core.money import Money
from core.provenance import ProvenanceGraph


class AccountType(str, enum.Enum):
    ASSET = "asset"
    LIABILITY = "liability"
    EQUITY = "equity"
    REVENUE = "revenue"
    EXPENSE = "expense"

    @property
    def normal_side(self) -> "Side":
        if self in (AccountType.ASSET, AccountType.EXPENSE):
            return Side.DEBIT
        return Side.CREDIT


class Side(str, enum.Enum):
    DEBIT = "debit"
    CREDIT = "credit"


@dataclass(frozen=True, slots=True)
class Account:
    code: str
    name: str
    type: AccountType


@dataclass(frozen=True, slots=True)
class JournalLine:
    account: Account
    side: Side
    amount: Money                    # always >= 0; direction is carried by `side`
    memo: str = ""
    provenance_id: str | None = None

    def signed(self) -> Decimal:
        """Debit-positive signed amount (for balance math)."""
        return self.amount.amount if self.side is Side.DEBIT else -self.amount.amount


@dataclass(frozen=True, slots=True)
class JournalEntry:
    id: str
    date: date
    description: str
    lines: tuple[JournalLine, ...]
    source_event_id: str
    policy_set: str = ""
    policy_version: str = ""
    reverses: str | None = None      # id of the entry this one reverses, if any


@dataclass
class CompiledJournal:
    """The result of one AIC compilation: entries + full provenance."""

    entries: list[JournalEntry] = field(default_factory=list)
    provenance: ProvenanceGraph = field(default_factory=ProvenanceGraph)
    policy_set: str = ""
    policy_version: str = ""

    def accounts(self) -> dict[str, Account]:
        out: dict[str, Account] = {}
        for entry in self.entries:
            for line in entry.lines:
                out[line.account.code] = line.account
        return out